Method and apparatus for feeding chips to a deposition location in a coating system

ABSTRACT

A device for storing and feeding chips to a deposition location in a coating system comprises a holder stack comprising a plurality of holders including first and last holders, a biasing element which applies a force to the last holder, and a pushing element which, when actuated, will push the first holder from a loading position to a deposition location adjacent to a deposition opening. There is also provided a method comprising loading a plurality of holders, each containing a chip, into a holding space, so that the holders are in the form of a holder stack, a force being applied by a biasing element to the last holder in the stack; and actuating a pushing element to push a first holder from the loading position to the deposition location. The method preferably further comprises passing a deposition material through the opening and then into contact with the chip.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 60/565,293, filed Apr. 26, 2004, the entirety of whichis incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to coating systems, in particular, to anapparatus for feeding chips to a deposition location in a coatingsystem. The present invention also relates to an apparatus for feedingchips to a measurement device in a system in which thin layers aredeposited onto substrates. The present invention further relates to amethod of feeding chips to a deposition location in a coating system.

BACKGROUND OF THE INVENTION

There are a wide variety of technologies which employ articles havingone or more thin layers of materials. Such thin layers can be formed inany of a variety of ways. For example, thin films for use in the fieldof optics as well as other applications are typically created throughdeposition processes such as chemical vapor deposition (CVD) andphysical vapor deposition (PVD).

In a CVD process, a source material is decomposed by heat within achamber of vacuum or low pressure. The material is subsequentlycondensed onto a target substrate, which has been biased to attract thevaporized material at a controlled rate to form a film of a specifiedthickness.

In a PVD process, the source material can be vaporized either throughsputtering or evaporation. Sputtering methodologies include DCsputtering and RF sputtering. Sputtering involves the bombardment of thesource material with a plasma or ion beam. Evaporation methods includethermal evaporation and electron beam evaporation. As with CVDprocesses, PVD processes occur within a chamber of vacuum or lowpressure and the vaporized source material is condensed onto a biased ornon-biased substrate at a controlled rate to form a film of a specifiedthickness.

CVD and PVD are just examples of a wide variety of methods employed fordepositing a material; the present invention is applicable to any methodfor depositing a material.

In many such devices which include such thin films, it is necessary toprecisely monitor one or more parameters of the film or films as theyare being deposited, e.g., in many devices, it is important to controlthe thickness of the thin film or films during the deposition process inorder to achieve the desired properties. Therefore precise measurementtechniques are required in situ and in real time. For example, in manycases it is important to monitor the thin film growth rate and thicknessand to ensure that the deposition process is stopped when the thin filmreaches the desired thickness.

Microbalances make use of the properties of a piezoelectric material,e.g., a quartz crystal (microbalances are just one example of a type ofsystem to which the present invention is applicable). When a physicalforce is applied to a piezoelectric material, electric charges build onopposite faces, thereby producing an electric field. By changing thesephysical forces at a specific rate, an oscillating voltage can beproduced. Conversely, when a voltage is applied, the piezoelectricmaterial will deform. Reversal of the polarity of the applied voltagewill cause the piezoelectric material to deform in the oppositedirection. Therefore, by applying a voltage from an alternating source,the material can be made to oscillate. When a voltage of a specificfrequency is applied, the quartz will oscillate with minimal resistance.This frequency is referred to as the resonant frequency.

As a thin film is deposited on a piezoelectric crystal through adeposition process, the thickness added by the thin film to the crystalcauses the resonant frequency to decrease. By closely monitoring changesin resonant frequency, resolutions of a few angstroms of thickness canbe realized. Typically, where such a microbalance is employed, themicrobalance is placed near the article or articles being produced, andthe conditions to which the microbalance is subjected are caused to beas similar as possible to the conditions to which the article orarticles being produced are subjected, so that the thickness orthickness growth detected by the microbalance can be assumed to beapproximately similar to the thickness or thickness growth occurring inthe article or articles being produced (alternatively, where conditionsdiffer, a tooling factor can be employed).

Crystals employed in a microbalance are designed to function effectivelyfor as long as possible, but they all fail eventually; some failprematurely (sometimes catastrophically). Such failure can occur becausethe thickness of the material deposited on the crystal just becomes solarge that the crystal can no longer function as accurately as needed ordesired. Sometimes a crystal cracks or otherwise fails before such alarge thickness of material is deposited.

In a typical microbalance, microprocessor controlled source voltage andoscillation sensors are connected to the crystal. The source voltage isapplied so as to cause the crystal to oscillate at its resonantfrequency. As the thin film is deposited on the crystal, thecorresponding decrease in the resonant frequency is sensed by themicroprocessor through the oscillation sensor. The microprocessor thenconverts the change in frequency to a deposition rate and thickness.

Thin film structures have greatly increased in complexity. Currently, itis not unusual for high-speed optical communications systems to demandstacks of alternating refractive index films which comprise up to 256layers.

The need to shut down a deposition process in order to replace a chip(e.g., a crystal) used in monitoring a deposition process (e.g.,thickness of deposited coating or rate of such thickness growth) iscertainly a drawback, usually a serious drawback, especially when itoccurs during the course of a sequence of depositing a large number oflayers.

Attempts have been made, with varying success, to provides ways by whicha monitoring procedure can be switched from monitoring using one chip tomonitoring using another chip without having to shut down a depositionprocess. There exists, however, an ongoing need for improvements indealing with situations where there is a desire or need to switch frommonitoring using one chip to monitoring using a different chip. Thisneed is particularly critical in light of the ever-increasing complexityof the structures being produced and the ever-increasing degrees ofaccuracy desired. Moreover, there is an ongoing need for devices whichmake it possible to switch from monitoring using one chip to monitoringusing a different chip in which the chips are reliably positioned withexcellent precision. There is further a need for such improvements whileminimizing increases in the size of the devices.

BRIEF SUMMARY OF THE INVENTION

In accordance with a first aspect of the present invention, there isprovided a device for storing and feeding chips to a deposition locationin a coating system, the device comprising:

a holder stack comprising a plurality of holders including at least afirst holder and a last holder, the first holder being positioned at aloading position, the last holder being positioned at an opposite end ofthe stack relative to the first holder, each of the plurality of holdersbeing in contact with at least one other of the holders, any holder inthe stack other than the first holder and the last holder being incontact with two others of the holders;

a biasing element which applies a force in a first direction to the lastholder, thereby applying a force to each of the holders by virtue of thecontact among the plurality of holders; and

a pushing element which, when actuated, will push the first holder fromthe loading position to a deposition location where the first holderwill be adjacent to or in contact with a portion of an interior surfaceof a deposition opening defining element, the deposition openingdefining element having an opening, the opening being substantiallycircumscribed by a boundary of the first holder when the first holder isin the deposition location.

Preferably, in this aspect of the invention, the device furthercomprises at least one electrode, a portion of the electrode beinglocated at a contact location such that when the first holder is locatedat the deposition location and a chip is contained within the firstholder, the chip contained within the first holder will make contactwith the portion of the electrode.

Preferably, in this aspect of the invention, a chip is located withineach holder, and each chip comprises a piezoelectric element, a firstelectrical contact and a second electrical contact, the first and secondelectrical contacts being spaced from each other and each being incontact with the piezoelectric element, or each chip comprises a glasselement, a first electrical contact and a second electrical contact, thefirst and second electrical contacts being spaced from each other andeach being in contact with the glass element.

In a further preferred aspect, the device further comprises a depositionsystem which, when activated, deposits material on a chip located in thefirst holder when the first holder is positioned in the depositionlocation.

In accordance with a second aspect of the present invention, there isprovided a device for storing and feeding chips to a deposition locationin a coating system, the device comprising:

a housing which defines a holding space;

a holder stack positioned within the holding space, the holder stackcomprising a plurality of holders including at least a first holder anda last holder, the first holder being positioned at a loading position,the last holder being positioned at an opposite end of the stackrelative to the first holder, each of the plurality of holders being incontact with at least one other of the holders, any holder in the stackother than the first holder and the last holder being in contact withtwo others of the holders;

a biasing element which applies a force in a first direction to the lastholder, thereby applying a force along the first direction to each ofthe holders by virtue of the contact among the plurality of holders, thefirst holder having a first surface which is pushed into contact with afirst surface of the holding space by virtue of the force applied in thefirst direction, the first surface of the holding space beingsubstantially perpendicular to the first direction; and

a pushing element which, when actuated, will push the first holder fromthe loading position along the first surface of the holding space in adirection substantially perpendicular to the first direction to adeposition location where the first holder will be adjacent to or incontact with a portion of an interior surface of a deposition openingdefining element, the deposition opening defining element having anopening, the portion of the interior surface substantiallycircumscribing the opening, the interior surface of the depositionopening defining element being substantially coplanar with the firstsurface of the holding space, whereby when the pushing element pushesthe first holder from the loading position to the deposition location,the first holder will slide substantially smoothly along the firstsurface of the holding space and the interior surface of the depositionopening defining element.

Preferably, in this aspect of the invention, as with the first aspect ofthe present invention, the device further comprises at least oneelectrode, a portion of the electrode being located at a contactlocation such that when the first holder is located at the depositionlocation and a chip is contained within the first holder, the chipcontained within the first holder will make contact with the portion ofthe electrode.

Preferably, in this aspect of the invention, as with the first aspect ofthe present invention, a chip is located within each holder, and eachchip comprises a piezoelectric element, a first electrical contact and asecond electrical contact, the first and second electrical contactsbeing spaced from each other and each being in contact with thepiezoelectric element, or each chip comprises a glass element, a firstelectrical contact and a second electrical contact, the first and secondelectrical contacts being spaced from each other and each being incontact with the glass element.

In a further preferred aspect, the device further comprises a depositionsystem which, when activated, deposits material on a chip located in thefirst holder when the first holder is positioned in the depositionlocation.

In accordance with a third aspect of the present invention, there isprovided a method of feeding chips to a deposition location in a coatingsystem, the method comprising:

loading a plurality of holders into a holding space, each of the holderscontaining a chip, so that the plurality of holders are in the form of aholder stack including at least a first holder and a last holder, thefirst holder being positioned at a loading position, the last holderbeing positioned at an opposite end of the stack relative to the firstholder, each of the plurality of holders being in contact with at leastone other of the holders, any holder in the stack other than the firstholder and the last holder being in contact with two others of theholders, a force being applied to the last holder by a biasing elementwhereby a force is applied to each of the holders by virtue of thecontact among the plurality of holders; and

actuating a pushing element to push the first holder from the loadingposition to a deposition location, where the first holder is in contactwith a portion of an interior surface of a deposition opening definingelement, the deposition opening defining element having an opening andthe opening being substantially circumscribed by a boundary of the firstholder.

Preferably, the method further comprises applying current through a chipcontained in the first holder, between the portion of the interiorsurface of the deposition opening defining element and at least oneelectrode in contact with the first chip, and the method furthercomprises depositing a deposition material onto a surface of the chip bypassing a deposition material through the opening and then into contactwith the chip.

Preferably, in the method of the third aspect of the present invention,when the first holder is moved from the loading position to thedeposition location, a second holder is moved by the force of thebiasing element to the loading position, and preferably the methodfurther comprises at a later time actuating the pushing element to pushthe first holder from the deposition location to a spent location, andthen actuating the pushing element to push the second holder from theloading position to the deposition location.

The invention may be more fully understood with reference to theaccompanying drawings and the following detailed description of theinvention.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

FIG. 1 is a sectional view taken along line 1-1 in FIG. 2 and inverted.

FIG. 2 is a top view of a device in accordance with the presentinvention (when the device is in use, it is preferably inverted, i.e.,such that the structure shown in FIG. 2 faces downward).

FIG. 3 is a front view of the device.

FIG. 4 is a close-up view of a portion of FIG. 1.

FIGS. 5 and 8 are perspective views of the device of FIG. 1, with ahousing cover 23 and a cartridge cover 24 (see FIG. 3) removed.

FIG. 6 is a perspective view of the device of FIG. 1.

FIG. 7 is a perspective view of the device of FIG. 1 with the housingcover 23, the cartridge cover 24 and the cartridge 25 (see FIG. 3)removed.

FIG. 9 is a view of an interior surface of the cartridge cover 24.

FIGS. 10 and 11 are back and front views, respectively, of an embodimentof a preferred holder in accordance with the present invention.

FIG. 12 is a side view of the holder shown in FIGS. 10 and 11.

FIG. 13 is a perspective view of the holder shown in FIGS. 10-12.

FIG. 14 is a sectional view along the line 14-14 in FIG. 10.

DETAILED DESCRIPTION OF THE INVENTION

As noted above, in accordance with a first aspect of the presentinvention, there is provided a device for storing and feeding chips to adeposition location in a coating system, the device comprising a holderstack, a biasing element and a pushing element.

Throughout the present specification, the expression “substantially” isused to mean at least 95% correspondence, e.g., where two planes arecharacterized as being “substantially parallel”, an angle defined bysuch planes is not more than about 4.5 degrees, a surface which is“substantially circumscribed” by one or more curves means that the oneor more curves include 95% of the length of a curve which circumscribesthe surface, “substantially perpendicular” means that an angle definedby a pair of surfaces is within the range of from 85.5 degrees to 94.5degrees, “substantially coplanar” means that an angle defined by a pairof surfaces is not more than about 4.5 degrees, and/or that 95% of thearea of each surface lies within a single plane.

The holder stack comprises a plurality of holders including at least afirst holder positioned at a loading position and a last holderpositioned at an opposite end of the stack relative to the first holder.Preferably, each of the holders has a first surface consisting of one ormore sections located in a first plane, a second surface consisting ofone or more sections in a second plane, and an outer peripheral edgeconsisting of one or more sections extending from the first surface tothe second surface, the first surface and second surface preferablybeing of substantially similar shapes and dimensions, the first planepreferably being substantially parallel to the second plane and beingspaced from the second plane by a distance which is much smaller thanthe dimensions of the first and second surfaces, whereby the holders canbe substantially aligned in the holder stack, i.e., such that the holderstack has a front surface (the first surface or the second surface ofthe first holder), a rear surface (the first surface or the secondsurface of the last holder) and one or more flat or curved side surfacesmade up of the outer peripheral edges of each of the holders in theholder stack (that is, where the outer peripheries of each of the firstand second surfaces of the respective holders are substantially squarewith rounded corners, the overall shape of the holder stack issubstantially square cylindrical with rounded edges).

In a specifically preferred embodiment of a holder in accordance withthe present invention, the holder comprises a first surface and a secondsurface, an opening being located in an interior of the first surfaceand extending toward the second surface, at least one lip portion havinga lip surface positioned between the first surface and the secondsurface, the lip surface extending into and blocking a portion of theopening, whereby a chip can be inserted into the opening through thefirst surface and the chip is prevented from passing through the holderby the at least one lip portion.

Preferably, one chip is located within each holder. Preferably, eachchip fits in the opening with relatively small tolerances, e.g., thelargest distance between a periphery of the chip and a surface of theopening is less than 1/10 of the largest dimension of the chip, morepreferably less than 1/20 of the largest dimension of the chip, morepreferably less than 1/40 of the largest dimension of the chip, evenmore preferably less than 1/60 of the largest dimension of the chip.Preferably, the tolerance is small enough that the chip is restrained,to at least some degree, from falling out of the opening (in thedirection opposite to the lip surface(s)) by virtue of contact between aperipheral edge of the chip and a peripheral edge of the opening.

A chip can be generally any article which can be employed in a devicewhich can be employed for monitoring a deposition of material in acoating system.

For example, in one embodiment of chips for use according to the presentinvention, the chips each comprise a piezoelectric element, a firstelectrical contact and a second electrical contact, the first and secondelectrical contacts being spaced from each other and each being incontact with the piezoelectric element (such a chip can be used tomonitor deposition of material in a coating system by applying currentto cause the piezoelectric element to vibrate, and monitoring changes inthe resonant frequency of such vibration). Such chips typically have atleast one substantially convex or substantially concave surface and/orat least one substantially flat surface. Typically, each such chip canbe oriented with either of its two major surfaces facing the depositionmaterial, i.e., the material can be deposited on either surface.

In another embodiment of chips for use according to the presentinvention, the chips each comprise a glass element, a first electricalcontact and a second electrical contact, the first and second electricalcontacts being spaced from each other and each being in contact with theglass element (such a chip can be used to monitor deposition of materialin a coating system by measuring resistivity across a chip as materialis being deposited on the chip). For example, such chips can be used asan in situ resistance monitor, which measures the sheet resistance of afilm (usually a thin film) during its deposition. Such measurement iscritical for manufacturing a number of articles, e.g., flat paneldisplay devices, semiconductors and similar thin film technologies. Anexample of an in situ resistance monitor is an IRM-4, an in situ fourpoint probe consisting of a square piece of glass (of any suitable size,e.g., up to 2 inches by up to 2 inches by up to 0.1 inch thick, such asabout ½ inch by ½inch by 0.020 inch thick or ½ inch by 1.5 inch by 0.020inch thick), having a deposited pattern which gives a sheet resistancereading when hooked to a power supply-such sensors can generally only beused once per run, making the device according to the present inventionparticularly useful in connection with such sensors.

The biasing element applies a force in a first direction to the rearsurface of the holder stack, i.e., to the last holder in the holderstack, thereby applying a force to each of the holders by virtue of thecontact among the plurality of holders. The biasing element can includeany biasing device or combination of biasing devices, e.g., a spring(linear, torsion or leaf), a piston-cylinder device, a bladder suppliedwith fluid under pressure, a diaphragm to which pressure is applied,etc. For example, a preferred embodiment of a biasing element for use inaccordance with the present invention comprises a linear compressionspring, one end of which abuts a fixed structure and the other end ofwhich abuts a first surface of a pressing plate, the pressing platehaving a second surface (opposite to the first surface) which appliesforce to the last holder in the stack. Preferably, the biasing elementapplies force continuously, although it is possible to construct adevice in which the biasing element applies force non-continuously (forexample, the biasing element can include a bladder containing fluid towhich pressure is applied non-continuously), e.g., only just before thepushing element begins to push a holder from the loading position to thedeposition position and while the pushing element pushes a holder fromthe loading position to the deposition.

Preferably, the device includes a housing which defines a holding spacehaving a first end, a second end and one or more sidewalls extendingfrom the first end to the second end, in which the holder stack ispositioned. Preferably, the holding space has interior dimensions suchthat the outer peripheral edges of the holders in the holder stack fitwithin the holding space with a relatively tight tolerance (e.g., thedistance from the outer peripheral edges of each holder to the nearestsidewall of the holding space is less than ⅕ of the largest dimension ofthe holders, preferably less than ⅛ of the largest dimension of theholders, more preferably less than 1/12 of the largest dimension of theholders, even more preferably less than 1/20 of the largest dimension ofthe holders). Preferably, the front surface of the holder stack (i.e.,the first or second surface of the first holder) abuts the first end ofthe holding space, and preferably, the force exerted by the biasingelement pushes the front surface of the holder stack against the firstend of the holding space. Preferably, the biasing element exerts forcebetween the second end of the holding space and the rear surface of theholder stack (i.e., the first or second surface of the last holder inthe holder stack). For example, where the biasing element comprises abiasing device (e.g., a compression spring) and a pressing plate,preferably, the biasing device exerts force between the second end ofthe holding space and the first surface of the pressing plate, and thesecond surface of the pressing plate is in contact with the rear surfaceof the holder stack.

The device can accommodate at least two holders, preferably at leastseven holders, more preferably at least twelve holders, even morepreferably about twenty holders (or even more). As holders are fed fromthe holder stack to the deposition location, the holder stack can bereplenished at any suitable time. For example, when the last holder inthe holder stack has been fed to the deposition location and needs to bereplaced, the holder stack needs to be replenished in order to supply anew holder to the deposition location. Preferably, however, the holderstack is replenished before the last holder is used, preferably at timeswhen the deposition process is shut down, e.g., after completion of arun (that is, when completed products are removed from the coatingsystem).

The pushing element, when actuated, will push the first holder from theloading position to the deposition location. For example, in anembodiment which includes a housing which defines a holding space, thepushing element preferably displaces the first holder by being pushedagainst the first holder, such that an end of the pushing element movesinto and occupies the loading position; after actuation of such apushing element, a first surface of the pushing element preferably willbe adjacent to or in contact with the first end of the holding space, asecond surface of the pushing element (the second surface of the pushingelement being substantially parallel to and opposite the first surfaceof the pushing element) preferably being in contact with a first surfaceof a next holder (the first surface of the next holder having been incontact with the second surface of the first holder before the pushingelement was actuated), the first surface of the next holder preferablybeing pushed, by virtue of the force applied to the rear surface of theholder stack by the biasing element, against the second surface of thepushing element (the next holder may also be the last holder, in whichcase the next holder has a second surface, opposite the first surface ofthe next holder, which is the rear surface of the holder stack).

When positioned at the deposition location, the first holder will beadjacent to or in contact with a portion of an interior surface of adeposition opening defining element. The deposition opening definingelement has an opening which is preferably substantially circumscribedby a boundary of the first holder when the first holder is in thedeposition location and/or which is preferably substantiallycircumscribed by the portion of the interior surface to which the firstholder is adjacent or with which the first holder is in contact. Theopening is provided such that material being deposited can pass throughthe opening and deposit onto a surface of a chip positioned inside thefirst holder.

The interior surface of the deposition opening defining element ispreferably substantially coplanar with the first surface of the holdingspace, whereby when the pushing element pushes the first holder from theloading position to the deposition location, the first holder will slidesubstantially smoothly along the first surface of the holding space andthe interior surface of the deposition opening defining element.

Preferably, there is further provided a deposition system which, whenactivated, deposits material on a deposition surface of a chip locatedin the first holder when the first holder is positioned in thedeposition location, and which deposits material on one or more otherstructures contained within a deposition chamber, the depositionlocation being exposed to the activity in the deposition chamber throughthe opening in the deposition opening defining element.

The device preferably further comprises at least one electrode, aportion of the electrode being located at a contact location such thatwhen the first holder is located at the deposition location and a chipis contained within the first holder, a back surface of the chipcontained within the first holder will make contact with the portion ofthe electrode. Preferably, the at least one electrode is biased, suchthat the portion of the electrode is urged toward the portion of theelectrode. Specifically preferred electrodes for use in accordance withthe present invention are pogo pins (such electrodes are well known tothose of ordinary skill in the art). Preferably, one or more pogo pinsare mounted such that for each pogo pin, a contact portion of the pogopin extends to an extended location when no external force is applied tothe pogo pin, and as a holder is pushed into the deposition location,the pogo pin(s) are retracted due to the force applied by the holder(i.e., in a direction opposite to the direction of the force exerted bythe pogo pins) to allow the holder to occupy the deposition location andsuch that the contact portion of each pogo pin is in contact with a backsurface of a chip contained within the holder, and such that each pogopin exerts a force against the back surface of the chip, therebymaintaining contact between each pogo pin and the back surface of thechip. In a specific preferred embodiment of the present invention, fourpogo pins are provided at locations which ensure that regardless of theorientation of the chip within the holder, at least one of the pogo pinsis in contact with a contact portion on the chip (i.e., an electrode),thereby ensuring electrical contact between at least one of the pogopins and the back surface of the chip.

Preferably, at least a part of the portion of the interior surface ofthe deposition opening defining element is an electrical contact.Preferably, the front surface of the chip within the holder in thedeposition location is in contact with the electrical contact on theinterior surface of the deposition opening defining element. Inembodiments where the at least one electrode is biased such that theelectrode is urged toward the back surface of the chip contained withinthe first holder, e.g., where the at least one electrode is one or morepogo pins in contact with the back surface of the chip, as describedabove, the biasing force preferably pushes the chip on the back surfacethereof so that the deposition surface of the chip is pressed againstthe electrical contact on the interior surface of the deposition openingdefining element.

Preferably, the electrical contact on the interior surface of thedeposition opening defining element and the at least one electrode areelectrically connected, e.g., via respective circuitries, to oppositesides of a power source, whereby an electrical circuit is defined by theelectrode, the chip in the holder at the deposition location and theelectrical contact. Any suitable circuitries can be employed forcompleting such circuit, and persons of skill in the art can readilyselect any of a wide variety of suitable circuitries; all suchcircuitries are within the scope of the present invention.

Preferably, e.g., when the chip in the first holder is no longer able toprovide the desired degree of accuracy, the pushing element can befurther actuated to push a holder from the deposition location to adiscard location. The pushing element is retractable, so that it canthen be retracted so that the second surface of the pushing element willno longer be in contact with the front surface of the holder stack(i.e., the first surface of the next holder), whereby the holder stackwill be pushed by the biasing element such that the next holder is inthe loading position, i.e., the next holder occupies substantially thespace which was occupied by the first holder prior to the first holderbeing pushed by the pushing element into the deposition location. Insuch a way, one-by-one, each of the holders in the holder stack can bemoved, in sequence, to the loading position, from the loading positionto the deposition location, and, after the chip in the holder hasperformed its sensing function in the deposition system, from thedeposition location to the discard location. As noted above, the holderstack can be replenished, i.e., one or more holders can be inserted, atany time, preferably in between deposition runs.

Alternatively, instead of the pushing element first pushing a holderfrom the deposition location to the discard and then pushing a holderfrom the loading position to the deposition location, the pushingelement can push a holder from the loading position to the depositionlocation, that holder simultaneously pushing another holder from thedeposition location to the discard location.

As noted above, in accordance with a third aspect of the presentinvention, there is provided a method of feeding chips to a depositionlocation in a coating system, the method comprising:

loading a holder stack into a holding space, each of the holderscontaining a chip, a first holder being positioned at a loadingposition, a force being applied to the last holder by a biasing elementwhereby a force is applied to each of the holders by virtue of thecontact among the plurality of holders;

actuating a pushing element to push the first holder from the loadingposition to a deposition location.

The descriptions of suitable holder stacks, holding spaces, chips,holders, loading positions, biasing elements, pushing elements anddeposition locations set forth above are applicable to this aspect ofthe present invention as well.

The method according to the third aspect of the present inventionpreferably further comprises applying current through a chip containedin the first holder, between the portion of the interior surface of thedeposition opening defining element and at least one electrode incontact with the chip.

As noted above, the method preferably further comprises passing adeposition material through the opening and then into contact with thechip, on which the deposition material deposits. The depositing can becarried out according to any deposition process, a wide variety of whichare well known to those of skill in the art, and can be carried in anydeposition chamber or other coating apparatus, a wide variety of whichare well known to those of skill in the art, and the present inventionencompasses all such deposition processes and coating apparatuses.

In accordance with a preferred modification according to the presentinvention, the chips themselves can be handled as holders, i.e., insteadof a holder stack, there can be provided a chip stack, and each chip canbe moved through the device in the way that the holders are moved inaccordance with the description set forth above. This modification isespecially effective in cases where the chips are in situ resistancemonitors as described above.

A preferred embodiment of a device for storing and feeding chips to adeposition location in a coating system in accordance with the presentinvention is shown in FIGS. 1-8. FIG. 1 is a sectional view taken alongline 1-1 in FIG. 2 and inverted. FIG. 2 is a top view of a device inaccordance with the present invention (when the device is in use, it ispreferably inverted, i.e., such that the structure shown in FIG. 2 facesdownward). FIG. 3 is a front view of the device. FIG. 4 is a close-upview of a portion of FIG. 1. FIGS. 5 and 8 are perspective views of thedevice, with a housing cover 23 and a cartridge cover 24 (see FIG. 3)removed. FIG. 6 is a perspective view of the device. FIG. 7 is aperspective view of the device with the housing cover 23, the cartridgecover 24 and the cartridge 25 (see FIG. 3) removed. FIG. 9 is a bottomview of the cartridge cover 24.

Referring to FIG. 1, there is shown a holder stack 10 comprising aplurality of holders 11-19 (more easily seen in FIG. 3), including afirst holder 11 and a last holder 19. The holder stack 10 is positionedwithin a holding space 50. The first holder 11 is in the loadingposition. The last holder 19 is positioned at an opposite end of thestack 10 relative to the first holder 11, and each of the plurality ofholders 11-19 is in contact with at least one other of the holders. Theholders 12-18 are each in contact with two others of the holders.

A biasing element 20 applies a force in a first direction (downward inthe perspective shown in FIG. 1) to the last holder 19, thereby applyinga force to each of the holders 11-19 by virtue of the contact among theplurality of holders. Referring to FIG. 7, the biasing element 20comprises a compression spring 21 and a pressing plate 22. The biasingelement thereby exerts force which presses the first surface 51 (seeFIG. 4) of the first holder 11 against the first surface 52 of theholding space 50 or against the pushing element 26 (as shown in FIG. 4).

The pushing element 26 is connected via a connector bar 27 and anactuator 28 to a stepper motor 34 which moves the actuator 28, theconnector bar 27 and the pushing element 26 between a first position(shown in FIG. 8) where the pushing element 26 is to the left (in theperspective shown in FIG. 1) of the loading position, a second positionwhere the pushing element 26 has moved to the right (in the perspectiveshown in FIG. 1) sufficiently far that the first holder is moved fromthe loading position to the deposition location (i.e., the arrangementas shown in FIGS. 1 and 4), and a third position where the pushingelement 26 has moved to the right (in the perspective shown in FIG. 1)sufficiently far that the first holder is moved from the depositionlocation to the discard location 28.

The device includes four pogo pin electrodes 29 (see FIG. 5), which areconnected electrically, via a plate 30 to a pair of electricalconductors 31 (see FIGS. 5 and 1), which terminate in contacts whichelectrically connect with a pair of pogo pin electrodes 32 when thecartridge 25 is installed on the base 33 (see FIG. 7). As a holder ispushed by the pushing element 26 from the loading position to thedeposition location, the pogo pin electrodes 29 are pushed inward (i.e.,toward the plate 30) to allow the holder to move into the depositionlocation, and the biasing of the pogo pin electrodes 29 forces the pogopin electrodes 29 toward the holder (i.e., away from the plate 30) suchthat the ends of the pogo pin electrodes 29 press against one surface ofthe chip 35 within the holder. The chip 35 is thereby biased toward aninterior surface 37 (see FIG. 9) of the cartridge cover 24. The exteriorsurface 38 of the cartridge cover 24 is shown in FIG. 2. The interiorsurface 37 of the cartridge cover 24 includes a contact area 39 whichsurrounds an opening 40 (see FIGS. 9 and 2) which extends from theinterior surface 37 to the exterior surface 38. The chip 35 is biased(as noted above) and is thereby pressed against the contact 39.

The pogo pin electrodes 32 are electrically connected to contactsthrough which electrical connection can be made to circuitry exterior tothe device. Similarly, the contact 39 is electrically connected tocontacts through which electrical connection can be made to circuitryexterior to the device. Accordingly, a circuit can be completed byconnecting opposite ends of a source of electrical power to therespective contacts, i.e., one end of the source of electrical power tothe contacts which are electrically connect to the pogo pin electrodes32, and the other end of the source of electrical power to the contactwhich is connected to the contact 39, such circuit being completed bythe electrical connection from the contact 39 to the chip 35, andthrough the chip 35 to the pogo pin electrodes 32. The chip 35 has adiameter which is larger than that of the opening 40. In thisembodiment, the interior surface 37 of the cartridge cover 24 functionsas the interior surface of a deposition opening defining element asdescribed above, the deposition opening defining element having anopening 40, the opening 40 being circumscribed by a boundary of a holderwhich is in the deposition location, and the portion of the interiorsurface with which such a holder is in contact circumscribing theopening 40.

As a holder is pushed by the pushing element 26 from the loadingposition to the deposition location, the holder slides smoothly alongthe interior surface 37 of the cartridge cover 24. After the holder hasbeen pushed by the pushing element 26 from the deposition location tothe discard location 28, the holder is then free to move, typically bythe force of gravity, into an adjacent first discard space 41 formed inthe cartridge cover 24 or into an adjacent second discard space 42 (seeFIG. 5) formed in the cartridge 25.

The exterior surface 38 of the cartridge cover 24 has a cone-shapedstructure 49 into which, during a deposition process, material beingdeposited passes on its way to coating the exposed surface of the chip(i.e., the surface of the chip which faces the opening 40).

The cartridge 25 is removably held in place on the base by tightening aset screw 36. The housing cover 23 and the cartridge cover 24 areremovably mounted on the. base 33 and the cartridge 25, respectively.

FIGS. 10 and 11 are back and front views, respectively, of an embodimentof a preferred holder in accordance with the present invention.Referring to FIG. 10, the holder has a first surface including regions43 and 44; referring to FIG. 11, the holder has a second surface 45. Theholder has an opening 46. As seen in FIG. 11, the holder has first andsecond lip surfaces 47 and 48 which are on opposite sides of respectivelip portions with respect to regions 43 and 44. In use, a chip is placedin the opening 46 of the holder such that the chip rests on the lipsurfaces 47 and 48. Preferably, the distance from the lip surfaces 47and 48 to the second surface 45 is greater than the thickness of thechip, such that when a plurality of holders, each containing one chip,are stacked, each chip is in contact with only the lip surfaces 47 and48 of the corresponding holder. FIG. 12 is a side view of the holdershown in FIGS. 10 and 11, FIG. 13 is a perspective view of the holdershown in FIGS. 10-12, and FIG. 14 is a sectional view along the line14-14 in FIG. 10. The holder shown in FIGS. 10-14 thus has a firstsurface consisting of two sections 43 and 44 located in a first plane, asecond surface consisting of one section 45 in a second plane, and anouter peripheral edge 53 consisting a plurality of sections extendingfrom the first surface to the second surface, the first surface andsecond surface being of substantially similar shapes and dimensions, thefirst plane being parallel to the second plane and being spaced from thesecond plane by a distance which is much smaller than the dimensions ofthe first and second surfaces. A plurality of such holders can thereforebe substantially aligned in the holder stack, i.e., such that the holderstack has a front surface (the first surface or the second surface ofthe first holder), a rear surface (the first surface or the secondsurface of the last holder) and one or more flat or curved side surfacesmade up of the outer peripheral edges of each of the holders in theholder stack. The overall shape of such holder stack will besubstantially square cylindrical with rounded edges.

Cooling fluid (e.g., water) inlet and outlet pipes 54 are shown in FIG.2, and the construction of such pipes, used to control the temperatureof components within the device, in particular, the chips, are wellknown to those of skill in the art.

The various components of the devices according to the present inventioncan be made of any suitable material, and persons of skill in the artcan readily make appropriate selections from among a wide variety ofsuch suitable materials, all of which choices are encompassed by thepresent invention. For example, the cooling fluid pipes may be formed ofstainless steel, the body of the base may be formed of stainless steelor aluminum, the body of the cartridge may be formed of aluminum, thebody of the cartridge cover may be formed of aluminum, and the body ofthe housing cover may be formed of aluminum.

Any two or more structural parts of the devices described above can beintegrated. Any structural part of the devices described above can beprovided in two or more parts which are held together, if necessary.Similarly, any two or more functions can be conducted simultaneously,and/or any function can be conducted in a series of steps.

1. A device for storing and feeding chips to a deposition location in acoating system, the device comprising: a holder stack comprising aplurality of holders including at least a first holder and a lastholder, said first holder being positioned at a loading position, saidlast holder being positioned at an opposite end of said stack relativeto said first holder, each of said plurality of holders being in contactwith at least one other of said holders, any holder in said stack otherthan said first holder and said last holder being in contact with twoothers of said holders; a biasing element which applies a force in afirst direction to said last holder, thereby applying a force to each ofsaid holders by virtue of said contact among said plurality of holders;and a pushing element which, when actuated, will push said first holderfrom said loading position to a deposition location where said firstholder will be adjacent to or in contact with a portion of an interiorsurface of a deposition opening defining element, said depositionopening defining element having an opening, said opening beingsubstantially circumscribed by a boundary of said first holder when saidfirst holder is in said deposition location.
 2. A device as recited inclaim 1, further comprising at least one electrode, a portion of saidelectrode being located at a contact location such that when said firstholder is located at said deposition location and a chip is containedwithin the first holder, said chip contained within said first holderwill make contact with said portion of said electrode.
 3. A device asrecited in claim 2, wherein said at least one electrode is biased, suchthat said portion of said electrode is urged toward said portion of saidelectrode.
 4. A device as recited in claim 2, wherein said at least oneelectrode is biased, such that said portion of said electrode is urgedin a direction which is substantially parallel to said first direction.5. A device as recited in claim 2, wherein at least a part of saidportion of said interior surface of said deposition opening definingelement is an electrical contact which is electrically connected to anopposite side of a power source relative to said electrode, whereby whensaid first holder contains a chip and is in said deposition location, anelectrical circuit is defined by said electrode, said chip and saidelectrical contact.
 6. A device as recited in claim 1, wherein a chip islocated within each said holder.
 7. A device as recited in claim 6,wherein each said chip comprises a piezoelectric element, a firstelectrical contact and a second electrical contact, said first andsecond electrical contacts being spaced from each other and each beingin contact with said piezoelectric element.
 8. A device as recited inclaim 6, wherein each said chip comprises a glass element, a firstelectrical contact and a second electrical contact, said first andsecond electrical contacts being spaced from each other and each beingin contact with said glass element.
 9. A device as recited in claim 1,further comprising a deposition system which, when activated, depositsmaterial on a chip located in said first holder when said first holderis positioned in said deposition location.
 10. A device as recited inclaim 1, wherein said first holder comprises a first surface and asecond surface, an opening being located in an interior of said firstsurface and extending toward said second surface, at least one lipportion having a lip surface positioned between said first surface andsaid second surface, said lip surface extending into and blocking aportion of said opening, whereby a chip can be inserted into saidopening through said first surface and said chip is prevented frompassing through said first holder by said at least one lip portion. 11.A device for storing and feeding chips to a deposition location in acoating system, the device comprising: a housing which defines a holdingspace; a holder stack positioned within said holding space, said holderstack comprising a plurality of holders including at least a firstholder and a last holder, said first holder being positioned at aloading position, said last holder being positioned at an opposite endof said stack relative to said first holder, each of said plurality ofholders being in contact with at least one other of said holders, anyholder in said stack other than said first holder and said last holderbeing in contact with two others of said holders; a biasing elementwhich applies a force in a first direction to said last holder, therebyapplying a force along said first direction to each of said holders byvirtue of said contact among said plurality of holders, said firstholder having a first surface which is pushed into contact with a firstsurface of said holding space by virtue of said force applied in saidfirst direction, said first surface of said holding space beingsubstantially perpendicular to said first direction; and a pushingelement which, when actuated, will push said first holder from saidloading position along said first surface of said holding space in adirection substantially perpendicular to said first direction to adeposition location where said first holder will be adjacent to or incontact with a portion of an interior surface of a deposition openingdefining element, said deposition opening defining element having anopening, said portion of said interior surface substantiallycircumscribing said opening, said interior surface of said depositionopening defining element being substantially coplanar with said firstsurface of said holding space, whereby when said pushing element pushessaid first holder from said loading position to said depositionlocation, said first holder will slide substantially smoothly along saidfirst surface of said holding space and said interior surface of saiddeposition opening defining element.
 12. A device as recited in claim11, further comprising at least one electrode, a portion of saidelectrode being located at a contact location such that when said firstholder is located at said deposition location and a chip is containedwithin the first holder, said chip contained within said first holderwill make contact with said portion of said electrode.
 13. A device asrecited in claim 12, wherein said at least one electrode is biased, suchthat said portion of said electrode is urged toward said portion of saidelectrode.
 14. A device as recited in claim 12, wherein said at leastone electrode is biased, such that said portion of said electrode isurged in a direction which is substantially parallel to said firstdirection.
 15. A device as recited in claim 12, wherein at least a partof said portion of said interior surface of said deposition openingdefining element is an electrical contact which is electricallyconnected to an opposite side of a power source relative to saidelectrode, whereby when said first holder contains a chip and is in saiddeposition location, an electrical circuit is defined by said electrode,said chip and said electrical contact.
 16. A device as recited in claim11, wherein a chip is located within each said holder.
 17. A device asrecited in claim 16, wherein each said chip comprises a piezoelectricelement, a first electrical contact and a second electrical contact,said first and second electrical contacts being spaced from each otherand each being in contact with said piezoelectric element.
 18. A deviceas recited in claim 16, wherein each said chip comprises a glasselement, a first electrical contact and a second electrical contact,said first and second electrical contacts being spaced from each otherand each being in contact with said glass element.
 19. A device asrecited in claim 11, further comprising a deposition system which, whenactivated, deposits material on a chip located in said first holder whensaid first holder is positioned in said deposition location.
 20. Adevice as recited in claim 11, wherein said first holder comprises saidfirst surface and a second surface, an opening being located in aninterior of said first surface and extending toward said second surface,at least one lip portion having a lip surface positioned between saidfirst surface and said second surface, said lip surface extending intoand blocking a portion of said opening, whereby a chip can be insertedinto said opening through said first surface and said chip is preventedfrom passing through said first holder by said at least one lip portion.21. A method of feeding chips to a deposition location in a coatingsystem, the method comprising: loading a plurality of holders into aholding space, each of said holders containing a chip, so that saidplurality of holders are in the form of a holder stack including atleast a first holder and a last holder, said first holder beingpositioned at a loading position, said last holder being positioned atan opposite end of said stack relative to said first holder, each ofsaid plurality of holders being in contact with at least one other ofsaid holders, any holder in said stack other than said first holder andsaid last holder being in contact with two others of said holders, aforce being applied to said last holder by a biasing element whereby aforce is applied to each of said holders by virtue of said contact amongsaid plurality of holders; and actuating a pushing element to push saidfirst holder from said loading position to a deposition location, wheresaid first holder is in contact with a portion of an interior surface ofa deposition opening defining element, said deposition opening definingelement having an opening and said opening being substantiallycircumscribed by a boundary of said first holder.
 22. A method asrecited in claim 21, further comprising applying current through a firstchip contained in said first holder, between said portion of saidinterior surface of said deposition opening defining element and atleast one electrode in contact with said first chip.
 23. A method asrecited in claim 22, further comprising passing a deposition materialthrough said opening and then into contact with said chip, on which saiddeposition material deposits.
 24. A method as recited in claim 21,further comprising passing a deposition material through said openingand then into contact with said chip, on which said deposition materialdeposits.
 25. A method as recited in claim 21, wherein when said firstholder is moved from said loading position to said deposition location,a second holder is moved by said force of said biasing element to saidloading position, and wherein said method further comprises: actuatingsaid pushing element to push said first holder from said depositionlocation to a discard location; and then actuating said pushing elementto push said second holder from said loading position to said depositionlocation.
 26. A device for storing and feeding chips to a depositionlocation in a coating system, the device comprising: a chip stackcomprising a plurality of chips including at least a first chip and alast chip, said first chip being positioned at a loading position, saidlast chip being positioned at an opposite end of said stack relative tosaid first chip, each of said plurality of chips being in contact withat least one other of said chips, any chip in said stack other than saidfirst chip and said last chip being in contact with two others of saidchips; a biasing element which applies a force in a first direction tosaid last chip, thereby applying a force to each of said chips by virtueof said contact among said plurality of chips; and a pushing elementwhich, when actuated, will push said first chip from said loadingposition to a deposition location where said first chip will be adjacentto or in contact with a portion of an interior surface of a depositionopening defining element, said deposition opening defining elementhaving an opening, said opening being substantially circumscribed by aboundary of said first chip when said first chip is in said depositionlocation.
 27. A device for storing and feeding chips to a depositionlocation in a coating system, the device comprising: a housing whichdefines a holding space; a chip stack positioned within said holdingspace, said chip stack comprising a plurality of chips including atleast a first chip and a last chip, said first chip being positioned ata loading position, said last chip being positioned at an opposite endof said stack relative to said first chip, each of said plurality ofchips being in contact with at least one other of said chips, any chipin said stack other than said first chip and said last chip being incontact with two others of said chips; a biasing element which applies aforce in a first direction to said last chip, thereby applying a forcealong said first direction to each of said chips by virtue of saidcontact among said plurality of chips, said first chip having a firstsurface which is pushed into contact with a first surface of saidholding space by virtue of said force applied in said first direction,said first surface of said holding space being substantiallyperpendicular to said first direction; and a pushing element which, whenactuated, will push said first chip from said loading position alongsaid first surface of said holding space in a direction substantiallyperpendicular to said first direction to a deposition location wheresaid first chip will be adjacent to or in contact with a portion of aninterior surface of a deposition opening defining element, saiddeposition opening defining element having an opening, said portion ofsaid interior surface substantially circumscribing said opening, saidinterior surface of said deposition opening defining element beingsubstantially coplanar with said first surface of said holding space,whereby when said pushing element pushes said first chip from saidloading position to said deposition location, said first chip will slidesubstantially smoothly along said first surface of said holding spaceand said interior surface of said deposition opening defining element.